Retrograde Intramedullary Nailing for Distal Femur Fractures: A Prospective Study of Functional Outcomes, Complications, and Union Rates

Background Distal third femur fractures, especially those with intra-articular extension, are challenging to manage and often lead to complications. Retrograde intramedullary nailing (RIN) has emerged as a minimally invasive alternative to traditional plating, offering advantages such as reduced soft tissue trauma, lower infection rates, and faster healing. This study aimed to evaluate the efficacy of RIN in managing distal femur fractures with associated soft tissue damage. Methods A prospective analysis was conducted involving 39 patients with distal femur fractures treated with retrograde nailing at Tirunelveli Government Medical College and Hospital between 2023 and 2025. Inclusion criteria included patients aged 20-70 years with AO type A1, A2, A3, C1, and C2 fractures, as well as Gustilo-Anderson type I and II fractures. Exclusion criteria included pathological fractures, periprosthetic fractures, and vascular injuries. Functional and radiological outcomes were assessed using the Modified Mize criteria and the Knee Society Scoring System. Results Functional outcomes were rated as excellent in 64.10% of patients, good in 30.77%, fair in 2.56%, and poor in 2.56%. The mean operative time was 94.36 ± 14.64 minutes, and the mean blood loss was 220 ± 47.60 ml for open nailing and 178.18 ± 38.28 ml for closed nailing. Union was achieved in 94.9% of cases, with one case of delayed union and one case of non-union requiring revision surgery. Knee stiffness was the most common complication observed, with an average knee flexion of 123.72 degrees. No infections or implant failures were reported. Conclusion RIN is an effective treatment for distal femur fractures, particularly in patients with soft tissue damage. It offers high union rates, low complication rates, and improved functional outcomes. However, surgeons should be mindful of potential complications such as knee stiffness and ensure adherence to postoperative rehabilitation protocols. This study contributes valuable insights into the use of intramedullary femur fixation for distal third femur fractures. Further multi-centre studies with larger sample sizes are recommended to validate these findings.